GB2470473A - Operation of a femtocell base station is restricted if a prohibited environment-related parameter is obtained - Google Patents

Abstract

A method of detecting an unauthorized operation of a femtocell base station comprises providing a femtocell base station in operative association with at least one cellular communication network in a particular physical environment 210. Parameters associated with the physical environment, including parameters of other networks, are obtained 220 and compared to predefined corresponding parameters to determine if the femtocell base station's operation is authorized 230. The obtained environment-related parameters may comprise the number of cellular communication devices camping or attempting to camp on the femtocell base station, wherein a corresponding prohibited environment-related parameter is a predefined number of cellular communications devices of a particular type. Optionally an alert responsive to the detecting of unauthorized operation of the femtocell base station is provided 250. Additionally updates in regard to the predefined list of parameters indicative of operation of the femtocell cellular communication femtocell base station in breach of regulatory rules associated with the particular cellular communication network may be provided 240.

Description

RESTRICTING REGIONAL FEMTOCELL OPERATION ADMISSION

BACKGROUND

1. TECHNICAL FIELD

[0001] The present invention relates to the field of cellular communication networks, and more particularly, to cellular communication femtocell base stations.

2. RELATED ART [0002] Prior to setting forth the background of the related art, it may be helpful to set forth definitions of certain terms that will be used hereinafter.

[0003] The term cellular communication network as used herein in this application, is defined as any radio frequency (RF) based communication network that is based upon geographical partition of space into cells. Each cell is provided with at least one base station that manages the wireless communication therein. Various cellular communication standards are cunently in use while other are being developed. The popular ones are: UMTS, HSPA, GSM, CDMA-2000, TD-SCDMA, LTE and WiMAX.

[0004] The term "Universal Mobile Telecommunications System" or "UMTS" as used herein in this application, is one of the third-generation (3G) cell phone technologies, which is also being developed through HSPA into a 4G technology.

Currently, the most common form of UMTS uses Wideband Code Division Multiple Access (W-CDMA) as the underlying air interface. W-CDMA is a wideband spread-spectrum mobile air interface that utilizes the direct-sequence spread spectrum method of asynchronous code division multiple access to achieve higher speeds and support more users compared to the implementation of time division multiplexing (TDMA) used by 2G GSM networks.

[0005] The term "Femtocell" or "femtocell base station or "Home NodeB" as used herein in this application, is the industry term for a small cellular communication base station, typically designed for use in residential, enterprise or small business environments. The ferntocell connects to the service provider's network via broadband Ethernet connection (such as DSL or cable). Current designs typically support two to eight mobile phones simultaneously in a residential setting. A femtocell allows service providers to extend service coverage and capacity indoors, especially where access would otherwise be limited or unavailable. The femtocell incorporates the functionality of a typical base station but extends it to allow a simpler, self contained deployment. By way of example, a UMTS femtocell may contain a Node B, RNC and GSN with Ethernet connection for backhaul. Femtocells may use different communication standards, including UMTS, HSPA, GSM, CDMA- 2000. TD-SCDMA, LTE and WiMAX. In a particular case, the 3G femtocell includes the functionality of the traditional Node-B and RNC, while using the standard 3G/HSPA interface to communicate with the cellular communication devices and the internet broadband access for backhauling to the mobile operator.

[0006] From a regulatory perspective, femtocells utilize RE signals within the licensed spectrum of national or regional cellular communication networks (mobile phones carriers). Therefore, one of the security threats and impediments in femtocell deployment is the risk that a particular femtocell unit (base station) that is sold to a customer for use exclusively at home/SoHo in one country, will be brought and used in a second country over the same or partial frequency used by a cellular communication network in the second country, thus resulting in uncontrolled interferences.

[0007] It should be noted that the aforementioned scenario may become common since the motivation of a femtocell user to use his or her femtocell in a second country is relatively high. The use of a femtocell abroad enables the user to use his or her mobile phone abroad, camped to the femtocell base station while paying femtocell tariffs instead of expensive roaming tariffs.

[0008] However, from the point of view of the cellular communication network of the second country, the operation of unauthorized femtocell within the coverage area of the cellular communication network is unacceptable because of, for example: unmanaged interference in his macro-networklfemtocells, potential collision with his macro-networks parameters, and loss of revenue in roaming calls.

[0009] Several solutions for restricting regional operation of femtocells are known in the art. One such solution comprises incorporating a Global Positioning System (GPS) within the femtocell base station, such that the femtocell is operational only in fr, specific geographical area. The disadvantage of this solution is the extra-cost involved in the implementation: extra hardware and software for each femtocell base station.

[0010] Another solution comprises detecting the femtocell location based on the dynamic IP address when connecting the femtocell over the internet. The disadvantages for that solution that it is not a robust solution -does not work properly under some circumstance, especially in the case where the ferntocell is located beyond proxies or femtocell gateways exists -in this case it's impossible to deduct the femtocell country location from the IP (Internet Protocol) address. Other situation where this solution fails is in the case of static IP address.

BRIEF SUMMARY

[0011] Embodiments of the present invention overcomes the aforementioned disadvantages of the existing art by providing a method of restricting the operation of a ferntocell configured to operate in one country, to that country exclusively, wherein the restriction exhibit a robust and cost effective solution.

[0012] According to one aspect of the invention, there is provided a control unit for a femtocell base station that being in operative association with a particular physical environment. The control unit comprises a regional restriction module, wherein the regional restriction module is arranged to: obtain from the particular physical environment, at least one environment-related parameter, and if at least one obtained environment-related parameter is one of a list exhibiting a plurality of predefined prohibited environment-related parameters, the control module restricts the operation of the femtocell base station according to a predefined manner.

[0013] According to another aspect of the invention, there is provided a method of detecting a prohibited operation of a femtocell base station, the method comprising: providing a femtocell base station within a particular physical environment; obtaining from the particular physical environment, at least one environment-related parameter; and if at least one obtained environment-related parameter is one of a list exhibiting a plurality of predefined prohibited environment-related parameters, restricting the operation of the femtocell base station.

[0014] These, additional, and/or other aspects and/or advantages of the present invention are: set forth in the detailed description which follows; possibly inferable from the detailed description; and/or learnable by practice of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] For a better understanding of the invention and to show how the same may be canied into effect, reference will now be made, purely by way of example, to the accompanying drawings in which like numerals designate corresponding elements or sections throughout.

[0016] In the accompanying drawings: [0017] FIG. 1 is a high level block diagram illustrating a cellular communication network according to some embodiments of the present invention; and [0018] FIG. 2 is a high level block diagram illustrating a cellular communication femtocell base station according to some embodiments of the present invention.

[0019] The drawings together with the following detailed description make apparent to those skilled in the art how the invention may be embodied in practice.

DETAILED DESCRIPTION

[0020] With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

[0021] Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is applicable to other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.

[0022] FIG. 1 is a high level block diagram illustrating a cellular communication femtocell base station 10 according to some embodiments of the present invention.

Cellular communication ferntocell base station 10 comprises: a control unit 110 comprising a regional restriction module 100; a memory unit 130; a storage unit 140; and an RF unit 150. Control unit 110, memory unit 130, storage unit 140, and the RF unit 150 are operable, in cooperation, to enable communication between at least one cellular communication device 30B camped on femtocell base station 10 and at least one cellular communication device (not shown) camped to a neighboring cellular communication base station (not shown) that is connected to femtocell base station 10 via PHY level 120, gateway 170 and networked connection 40.

[0023] Femtocell base station 10 is operatively associated with a particular physical environment 50 which is the environment that is being accessed by Femtocell base station 10 via RF unit 150. Physical environment 50 exhibits a plurality of characteristics such as active neighboring networks -their identifiers and patterns, camped and un-camped cellular communication devices and further attributes that correspond with the geographical location in which femtocell base station 10 has been set. A plurality of environment-related parameters may be obtained by femtocell base station 10 from physical environment 50.These environment-related parameters are used, in embodiments of the present invention, to determine whether femtocell base station 10 has been set in a prohibited location and consequently restrict its operation.

[0024] According to some embodiments of the invention, regional restriction module is arranged to instruct femtocell base station 10 to scan physical environment 50, obtain environment-related parameters and make a decision as to whether femtocell base station 10 has been located in an unauthorized region, based on predefined environment-related parameters.

[0025] According to some embodiments of the invention, a list of prohibited environment-related parameters may be defined for each particular femtocell base station 10. Regional restriction module 100 is adapted to determine an occurrence of at least one prohibited environment-related parameter and consequently restrict the operation of femtocell base station 10.

[0026] According to some embodiments of the invention, the list of prohibited environment-related parameters may be selected from a list of identifiers of cellular networks present in physical environment 50 in which femtocell base station 10 is set.

[0027] The aforementioned cellular network identifiers may comprise: [0028] PLMN id -the list of all possible public land mobile network (PLMN) ID in the home country. For example, in the state of Israel, the list of PLMN IDs should include the PLMN IDs of Pelephone, Partner, Celicorn, Paltel and any other operator of a neighboring country (such as Jordan) capable of being received in Israel.

Frequencies of home networks. For example, in Israel, the list of the frequencies used by Pelephone, Partner, Celicom, Paltel and any other operator of a neighbor country capable of being received in Israel Base Station Identity Code (BSIC) or Network Color Code (NCC), for 2G networks -The list of all possible BSIC/NCC in the home country a cellular communication device/femtocell would optionally receive in the home country; and thresholds for the number of roaming or emergency cellular communication devices.

[0029] According to some embodiments of the invention, another prohibited environment-related parameter may be a number of cellular communication devices camping (or attempting to camp) on femtocell base station 10 beyond a predefined threshold. For example: In case of open femtocells (allowing any cellular network device to camp thereon), the number of roaming/barred cellular communication devices to the femtocell with an International Mobile Subscriber Identity (IMSI) specific to one foreign country is unreasonable. For example, if on an Israeli femtocell base station 10 (associated with an Israeli operator) a high number of different cellular communication devices are camping in a predefined period of time, and all these have an IMSI with Mobile Communications Component (MCC) of Australia, it is reasonable to believe that femtocell base station 10 is now used in Australia and therefore it is illegally used.

[0030] According to some embodiments of the invention, if the amount or rate of roaming attempts by the same cellular communication device is unreasonable -the restriction module 100 determines an unauthorized use of femtocell base station 10.

The aforementioned feature is based upon the idea that an Australian cellular communication device, for example, going in out of the femtocell area will perform an unreasonable number of roaming attempts in a short time. Further the roaming time between the country of femtocell base station 10 and the suspect country is impossibly low, below the fastest travelling time.

[0031] According to some embodiments of the invention, the amount of attempts done by these roaming cellular communication devices with incorrect numbers on femtocell base station 10 is above a predefined threshold. Notably, these cellular communication devices dont know they have roamed, so they use femtocell numbers without prefix and therefore fail to dial on the illegal femtocell base station 10.

[0032] According to some embodiments of the invention, in case of closed femtocell base station 10 (restricting camping thereon to specific cellular communication devices), the amount of different barred cellular communication devices (possible camped in emergency mode) is above a threshold can also serve as an indication of femtocell usage outside the legal scope of the cellular communication device.

[0033] According to some embodiments of the invention, due to dynamic changes in telecommunication industry in each country, the aforementioned lists may need to be updated from time to time. It is expected the femtocells to include remote updates feature enabling these lists to get updated from time to time.

[0034] FIG. 2 is a high level flowchart illustrating a method according to some embodiments of the present invention. The flowchart shows a method of detecting a prohibited operation of a femtocell base station. The method comprising: providing a femtocell base station in a particular physical environment 210; obtaining from the particular physical environment, at least one environment-related parameter 220; if at least one obtained environment-related parameter is one of a list exhibiting a plurality of predefined prohibited environment-related parameters, restricting operation of the femtocell base station 230; optionally updating the list exhibiting a plurality of predefined prohibited environment-related parameters 240; optionally alerting a predefined entity as to the prohibited operation of the femtocell base station 250.

[0035] According to some embodiments of the invention, the method further comprises using one of two scanning techniques to identify whether an impossible network sunounds the femtocells. The first is direct scanning in which the femtocell scans all the downlink frequencies over all the bands (in its capabilities), using the ferntocell sniffer mode to identify any network having a PLMN outside list, transmitting at a frequency outside list or having a BSIC/NCC outside list. The direct scanning may include one or more technologies, for example: 2G bands, 3G bands, and the like, either for GSM or UMTS networks.

[0036] The second type of scanning is indirect scanning, in which the femtocell requests all the handsets that have camped on the femtocell, to perform inter-measurements on a different frequency. The measurements reports send by the handsets to the femtocell will provide the info to the femtocell to identify whether any impossible network surrounds any of the handsets. The ferntocell will manage the scanning of the inter-frequencies over all the bands by asking the handsets for measurements on one freq on a time.

[0037] The indirect scanning could include one or more technology -for example 2G bands, 3G bands, etc. for GSM or UMTS networks. It should be noted that 3G handsets are requested to support measurements over 2G/GSM and 3G/UMTS as dictated by the 3G base station they are camped on. Specifically, in the aforementioned feature the femtocell will look for inconsistencies in any of the lists in view of the measurements reports.

[0038] According to some embodiments of the invention, in the case that any of the aforementioned processes discover an illegitimate (logically impossible) network sulTounding the femtocell base station, it will disable permanently or temporarily the operation of the femtocell base station. Optionally, an alarm message will be send to the home network informing unauthorized use of the femtocell.

[0039] Specifically, in 3G UMTS femtocells, the method comprises: scanning through use of MEASUREMENT REQUEST primitives over inter-frequencies. The femtocell base station shall ask the camped cellular communication device to report, e.g. the RSSI, RSCP, ECIO, PLMN ID, BSIC/NCC found over each frequency scanned in the inter-freq. The femtocell will perform the scanning frequency by frequency. Thus, the femtocell base station will use the measurements capabilities of the camped cellular communication device in order to sniff the environment outside the femtocell to identify any other PLMNs/BSIC-NCC or suspect frequencies used for other networks operation.

[0040] According to some embodiments, scanning over inter-frequency can be in the same or other cellular technology. For example a UMTS femtocell base station will scan for suspect remote networks that work either in UMTS, GSM or CDMA2000 technologies.

[0041] According to some embodiments, completing scanning without detecting any impossible network will trigger the authorization for opening the femtocell to normal full operation.

[0042] Advantageously, embodiments of the present invention avoid misuse of licensed spectrum by criminal users, trying to use the femtocell outside their legitimate carrier geographical coverage or scope.

[0043] Advantageously, some femtocells include a feature of "secure boot". This feature prevents changing any of the femtocell SW contents by any hacker. Therefore in a femtocell equipped with the aforementioned feature and the aforementioned conect lists, it will be impossible to bypass these technique security mechanism or to change the lists contents [0044] Advantageously, various embodiments of the invention are aimed for the UMTS femtocells market. However, it is understood that the necessary modification may be performed in order to support any kind of cellular communication, in any standard. Thus, it can similarly be applicable to the LTE, TD-SCDMA, CDMA2000, Wimax and GSM.

[0045] According to some embodiments of the invention, the restricting module may be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations thereof. Preferably, the base band processor with the regional restriction functionality is implemented as an application specific integrated circuit (ASIC) thus allowing optimization of the performance while keeping cost relatively low.

[0046] Suitable processors modules within the ASIC implementation of the base band processors include, by way of example, digital signal processors (DSPs) but also general purpose microprocessors, and field programmable gate array (FPGA).

Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memories for storing instructions and data. Generally, a computer will also include, or be operatively coupled to communicate with, one or more mass storage devices for storing data files.

Storage devices suitable for tangibly embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices.

[0047] In the above description, an embodiment is an example or implementation of the inventions. The various appearances of "one embodiment," "an embodiment" or "some embodiments" do not necessarily all refer to the same embodiments.

[0048] Although various features of the invention may be described in the context of a single embodiment, the features may also be provided separately or in any suitable combination. Conversely, although the invention may be described herein in the context of separate embodiments for clarity, the invention may also be implemented in a single embodiment.

[0049] Reference in the specification to "some embodiments", "an embodiment, "one embodiment" or "other embodiments' means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the inventions.

[0050] It is to be understood that the phraseology and terminology employed herein is not to be construed as limiting and are for descriptive purpose only.

[0051] The principles and uses of the teachings of the present invention may be better understood with reference to the accompanying description, figures and examples.

[0052] It is to be understood that the details set forth herein do not construe a limitation to an application of the invention.

[0053] Furthermore, it is to be understood that the invention can be carried out or practiced in various ways and that the invention can be implemented in embodiments other than the ones outlined in the description above.

[0054] It is to be understood that the terms "including", "comprising", "consisting" and grammatical variants thereof do not preclude the addition of one or more components, features, steps, or integers or groups thereof and that the terms are to be construed as specifying components, features, steps or integers.

[0055] If the specification or claims refer to "an additional" element, that does not preclude there being more than one of the additional element.

[0056] It is to be understood that where the claims or specification refer to "a" or "an" element, such reference is not be construed that there is only one of that element.

[0057] It is to be understood that where the specification states that a component, feature, structure, or characteristic "may", might", "can" or "could" be included, that particular component, feature, structure, or characteristic is not required to be included.

[0058] Where applicable, although state diagrams, flow diagrams or both may be used to describe embodiments, the invention is not limited to those diagrams or to the conesponding descriptions. For example, flow need not move through each illustrated box or state, or in exactly the same order as illustrated and described.

[0059] Methods of the present invention may be implemented by performing or completing manually, automatically, or a combination thereof, selected steps or tasks.

[0060] The term "method" may refer to manners, means, techniques and procedures for accomplishing a given task including, but not limited to, those manners, means, techniques and procedures either known to, or readily developed from known manners, means, techniques and procedures by practitioners of the art to which the invention belongs.

[0061] The descriptions, examples, methods and materials presented in the claims and the specification are not to be construed as limiting but rather as illustrative only.

[0062] Meanings of technical and scientific terms used herein are to be commonly understood as by one of ordinary skill in the art to which the invention belongs, unless otherwise defined.

[0063] The present invention may be implemented in the testing or practice with methods and materials equivalent or similar to those described herein.

[0064] Any publications, including patents, patent applications and articles, referenced or mentioned in this specification are herein incorporated in their entirety into the specification, to the same extent as if each individual publication was specifically and individually indicated to be incorporated herein. In addition, citation or identification of any reference in the description of some embodiments of the invention shall not be construed as an admission that such reference is available as

prior art to the present invention.

[0065] While the invention has been described with respect to a limited number of embodiments, these should not be construed as limitations on the scope of the invention, but rather as exemplifications of some of the prefened embodiments.

Other possible variations, modifications, and applications are also within the scope of the invention. Accordingly, the scope of the invention should not be limited by what has thus far been described, but by the appended claims and their legal equivalents.

Claims (16)

1. CLAIMSWhat is claimed is: 1. A control unit for a femtocell base station that is in operative association with a particular physical environment, the control unit comprising: a regional restriction module, wherein the regional restriction module is ananged to: obtain from the particular physical environment, at least one environment-related parameter; and if at least one obtained environment-related parameter is one of a list exhibiting a plurality of predefined prohibited environment-related parameters, restrict operation of the femtocell base station based on a predefined manner.
2. 2. The control unit according to claim 1, wherein the obtaining from the particular physical environment, at least one environment-related parameter is performed directly by the femtocell base station, and wherein the environment-related parameter comprises at least one parameter of at least one cellular communication network operative within the particular physical environment of the femtocell base station.
3. 3. The control unit according to claim 1, wherein the obtaining from the particular physical environment, at least one environment-related parameter is performed indirectly by inquiring at least one cellular communication device camped on the femtocell base station, and
4. 4. The control unit according to claim 3, wherein the environment-related parameter comprises at least one parameter of at least one cellular communication network operative within the particular physical environment of the ferntocell base station and identified by the at least one camped cellular communication device.
5. 5. The control unit according to claim 1, wherein the at least one obtained environment-related parameter comprises a number of cellular communication devices camping or attempting to camp on the femtocell base station, wherein corresponding prohibited environment-related parameter is a predefined number of cellular communication devices camping or attempting to camp on the femtocell base station all of a particular predefined type.
6. 6. The control unit according to claim 5, wherein the particular predefined type is a cellular communication device in one of: a roaming mode, an emergency mode.
7. 7. The control unit according to claim 1, wherein the control unit is further arranged to update the list exhibiting a plurality of predefined prohibited environment-related parameters.
8. 8. The control unit according to claim 1, wherein the control unit is further ananged to alert a predefined entity as to the prohibited operation of the femtocell base station.
9. 9. A method of detecting a prohibited operation of a femtocell base station, the method comprising: providing a femtocell base station within a particular physical environment; obtaining from the particular physical environment, at least one environment-related parameter; and if at least one obtained environment-related parameter is one of a list exhibiting a plurality of predefined prohibited environment-related parameters, restricting operation of the ferntocell base station.
10. 10. The method according to claim 9, wherein the obtaining from the particular physical environment, of at least one environment-related parameter is performed directly by the femtocell base station, and wherein the environment-related parameter comprises at least one parameter of at least one cellular communication network operative within the particular physical environment associated with the femtocell base station.
11. 11. The method according to claim 9, wherein the obtaining from the particular physical environment, of at least one environment-related parameter is performed indirectly by inquiring at least one cellular communication device camped on the femtocell base station.
12. 12. The method according to claim 11, wherein the environment-related parameter comprises at least one parameter of at least one cellular communication network active within the particular physical environment of the femtocell base station and identified by the at least one camped cellular communication device.
13. 13. The method according to claim 9, wherein the at least one obtained environment-related parameter comprises a number of cellular communication devices camping or attempting to camp on the femtocell base station, wherein colTesponding prohibited environment-related parameter is a predefined number of cellular communication devices camping or attempting to camp on the femtocell base station all of a particular predefined type.
14. 14. The method according to claim 13, wherein the particular predefined type is a cellular communication device in one of: a roaming mode, an emergency mode.
15. 15. The method according to claim 9, further comprising updating the list exhibiting a plurality of predefined prohibited environment-related parameters
16. 16. The method according to claim 9, further comprising alerting a predefined entity as to the prohibited operation of the femtocell base station.